Trihalogen arylthioglycolic acids and process of making same



latented June 23, 1931 UNITED STATES RICHARD HERZ, OF FBANKFORT-ON-THE-MAIN, ERNST RUNNE, OF FRANKFORT-ON- THE-MAIN-HOCHST, AND EDUARD ALBRECHT, Oil

FRANKFORT-ON-THE-I'JAIN- EECHENHEIM, GERMANY, .ASSIGNORS 'TO GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE TRIHALOGEN ARYLTHIOGLYGOLIC ACIDS AND PROCESS OF MAKING S AME No Drawing. Original application filed. March 15, 1928, Serial No. 262,031, and in Germany March 18,

1927. Divided and this application filed. February 13, 1930.

This application is a division of our application Serial No. 262,031, filed March 15, 1928.

We have found that by treating trihalogen benzene derivatives particularly those corresponding to the general formula:

X Y r in which formula the Xs mean halogen and Y means hydrogen or an alkylgroup, with chlorosulfonio acid, uniform sulfochlorides are formed. It is a surprising fact that this reaction produces uniform sulfochlorides as according to the behaviour of toluene the formation of several isomeric sulfochlorides was to be expected. These sulfochlorides are reduced to the corresponding mercapt-ane compounds and yield by condensing the latter with monochloracetic acid trihalogenarylthioglycolic acids of the general formula:

wherein X and Y have the aforesaid signification.

Our present process is more economical and yields the desired products in a purer state than the hitherto generally applied process starting from the corresponding amino-compounds and subjecting them to the so called Leukards reaction.

The trihalogenarylthioglycolic acid, obtained according to our process, are new compounds and represent valuable intermediates for the production of dyestuffs of the thioindigo series.

In order to further illustrate our invention, the following examples are given, the

Serial No. 428,238.

E sample 1 (a) Production of 1.2.3-trich1orobenzene-4- sulfochloride of the formula:

182 parts of 1.2.2-trichl0robenzene of the melting point 53-54" (cf. Beilstein, ath edition, vol. 5, page 203) are introduced at 2030 into 7 parts of chlorosulfonic acid.

The mixture is slowly heated to about 3 and kept at this temperature for about 2 hours while stirring. \Vhen cold the mass is poured on ice, the separated sulfochloride is filtered off and directly used for the further process. This new compound melts in a pure state at about 6566.

(6) Production of 1.2.3-trichlorobenzene- -mercaptane of the formula The mercaptane compound described sub (6) is dissolved at about 10 in 520 parts of a caustic soda solution of 33 B. and 3000 parts of water and miXed with 100 parts of mono-chloro-acetic acid. Then the mass is stirred at about 50 for an hour. After cooling down the precipitated sodium salt of the formed 1.2.3-trichloro-benzenel-thioglycolic acid is filtered off. By acidifying the free acid may be obtained therefrom as white needles of the melting point 149.

Example 2 1411240011 I't melts at about 157161.

We claim 1. A process for manufacturing phenylf thioglycolic acids of the general formula:

- a i X win-coon in which formula the Xs mean halogen and Y means hydrogen or an alkyl group which process comprises treating halogen-benzenes l of the general formula:

XmY

'in which formula the Xs and Y have the aforesaid signification, with chlorosulfonic acid at a temperature below 100 (1, reducing' the sulfochlorides thus formed to the corresponding mercaptane compounds and 3. As a new product 1.2.3-trichlorobenzenet-thioglycolic acid of the formula:

7 dGHzCOOH being when dry a white crystalline powder melting at about 149, insoluble in water,

soluble in alkalis which can'becondensed to trichloro-oxythionaphthene. V p y In testimony whereof we, afii'x our signatures.

RICHARD HERZ. ERNST RUNNE. V EDUARD ALBRECHT.

condensing thelatter with monochloroacetic acid. I

2. As new compounds products correspond ing probably to the general formula:

X a v Y t-om-ooon' in which formula the Xs mean chlorine and Y means hydrogen or an alkyl group, being crystalline powders, insoluble in alkalis which can be condensed to the corresponding oxythionaphthenederivatives. 

